Contact using multilayer liner

Abstract

An opening is formed within a substrate made of a silicon material, and a cleaning process is performed; after which, the bottom and walls of the opening are contaminated with oxygen and fluorine particles. A lower blocking layer is formed within the opening, and the lower blocking layer contacts the bottom and walls of the opening. Also, a middle liner layer is formed within the opening, and the middle liner layer contacts the lower blocking layer. Additionally, an upper blocking layer is formed within the opening, and the upper blocking layer contacts the middle liner layer. Further, a conductor layer is formed within the opening, and the conductor layer contacts the upper blocking layer. The lower blocking layer prevents the fluorine particles from affecting the other layers.

What is claimed is: 
     
       1. A device comprising:
 a substrate of a multi-layer integrated circuit device, said substrate comprising silicon; 
 an opening within the substrate, and a surface of the opening is contaminated with oxygen and fluorine particles; 
 a lower blocking layer within the opening, and the lower blocking layer contacts the surface of the opening; 
 a middle liner layer within the opening, and the middle liner layer contacts the lower blocking layer; 
 an upper blocking layer within the opening, the upper blocking layer contacts the middle liner layer, and the middle liner layer is between the lower blocking layer and the upper blocking layer; and 
 a conductor layer within the opening, and the conductor layer contacts the upper blocking layer and comprises a conductive contact within the multi-layer integrated circuit device. 
 
     
     
       2. The device according to  claim 1 , the oxygen and fluorine particles are within an area of the substrate adjacent the lower blocking layer. 
     
     
       3. The device according to  claim 1 , each of the lower blocking layer and the upper blocking layer comprise titanium composite materials selected from a group consisting of titanium nitride (TiN), titanium silicide (TiSi), titanium carbide (TiC), and titanium alumide (TiAl)) when the middle liner layer comprises titanium (Ti);
 each of the lower blocking layer and the upper blocking layer comprise tungsten composite materials selected from a group consisting of fluorine-free tungsten (FFW), tungsten nitride (WN), and tungsten carbide (WC) when the middle liner layer comprises tungsten (W); 
 each of the lower blocking layer and the upper blocking layer comprise tantalum composite materials selected from a group consisting of tantalum nitride (TaN) when the middle liner layer comprises tantalum (Ta); and 
 each of the lower blocking layer and the upper blocking layer comprise nickel composite materials selected from a group consisting of nickel silicide when the middle liner layer comprises nickel (Ni). 
 
     
     
       4. The device according to  claim 1 , the upper blocking layer is thicker than the lower blocking layer. 
     
     
       5. The device according to  claim 1 , the upper blocking layer is at least three times thicker than the lower blocking layer. 
     
     
       6. The device according to  claim 1 , the middle liner layer comprises an oxide. 
     
     
       7. The device according to  claim 6 , the oxide within the middle liner layer comprises the oxygen scavenged from the surface of the opening. 
     
     
       8. A device comprising:
 a substrate of a multi-layer integrated circuit device, said substrate comprising silicon, and the substrate has a surface; 
 an opening within the substrate, the opening has opening walls perpendicular to the surface of the substrate, the opening has a bottom parallel to the surface of the substrate, the bottom of the opening is positioned distal to the surface of the substrate, and the bottom of the opening and the opening walls are contaminated with oxygen and fluorine particles; 
 a lower blocking layer within the opening, and the lower blocking layer contacts the bottom of the opening and the opening walls; 
 a middle liner layer within the opening, and the middle liner layer contacts the lower blocking layer; 
 an upper blocking layer within the opening, the upper blocking layer contacts the middle liner layer, and the middle liner layer is between the lower blocking layer and the upper blocking layer; and 
 a conductor layer within the opening, and the conductor layer contacts the upper blocking layer and comprises a conductive contact within the multi-layer integrated circuit device. 
 
     
     
       9. The device according to  claim 8 , the oxygen and fluorine particles are within an area of the substrate adjacent the lower blocking layer. 
     
     
       10. The device according to  claim 8 , each of the lower blocking layer and the upper blocking layer comprise titanium composite materials selected from a group consisting of titanium nitride (TiN), titanium silicide (TiSi), titanium carbide (TiC), and titanium alumide (TiAl)) when the middle liner layer comprises titanium (Ti);
 each of the lower blocking layer and the upper blocking layer comprise tungsten composite materials selected from a group consisting of fluorine-free tungsten (FFW), tungsten nitride (WN), and tungsten carbide (WC) when the middle liner layer comprises tungsten (W); 
 each of the lower blocking layer and the upper blocking layer comprise tantalum composite materials selected from a group consisting of tantalum nitride (TaN) when the middle liner layer comprises tantalum (Ta); and 
 each of the lower blocking layer and the upper blocking layer comprise nickel composite materials selected from a group consisting of nickel silicide when the middle liner layer comprises nickel (Ni). 
 
     
     
       11. The device according to  claim 8 , the upper blocking layer is thicker than the lower blocking layer. 
     
     
       12. The device according to  claim 8 , the upper blocking layer is at least three times thicker than the lower blocking layer. 
     
     
       13. The device according to  claim 8 , the middle liner layer comprises an oxide. 
     
     
       14. The device according to  claim 13 , the oxide within the middle liner layer comprises the oxygen scavenged from the bottom and the opening walls of the opening.